[alternative-merged] clocksource-disallow-setting-jiffies-as-the-clocksource.patch removed from -mm tree

[alternative-merged] clocksource-disallow-setting-jiffies-as-the-clocksource.patch removed from -mm tree

[akpm]

The patch titled
     clocksource: disallow setting jiffies as the clocksource
has been removed from the -mm tree.  Its filename was
     clocksource-disallow-setting-jiffies-as-the-clocksource.patch

This patch was dropped because an alternative patch was merged

The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/

------------------------------------------------------
Subject: clocksource: disallow setting jiffies as the clocksource
From: Luming Yu <luming.yu@gmail.com>

As reported in https://bugzilla.redhat.com/show_bug.cgi?id=496028,

	echo jiffies > clocksource0/current_clocksource

makes the system crash.

I reproduced the problem with upstream kernel.  The root cause is that
jiffies is just a variable in memory, it relies on other clock source to
tick, and it never ticks on itself.

Signed-off-by: Yu Luming <luming.yu@intel.com>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 kernel/time/clocksource.c |    5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff -puN kernel/time/clocksource.c~clocksource-disallow-setting-jiffies-as-the-clocksource kernel/time/clocksource.c
--- a/kernel/time/clocksource.c~clocksource-disallow-setting-jiffies-as-the-clocksource
+++ a/kernel/time/clocksource.c
@@ -504,8 +504,9 @@ static ssize_t sysfs_override_clocksourc
 		/* try to select it: */
 		list_for_each_entry(cs, &clocksource_list, list) {
 			if (strlen(cs->name) == len &&
-			    !strcmp(cs->name, override_name))
-				ovr = cs;
+			    !strcmp(cs->name, override_name) &&
+				cs != &clocksource_jiffies)
+					ovr = cs;
 		}
 	}
 
_

Patches currently in -mm which might be from luming.yu@gmail.com are

linux-next.patch
clocksource-disallow-setting-jiffies-as-the-clocksource.patch